Semiconductor devices, such as fin field effect transistors (FinFETs) can include fin shaped bodies and epitaxial layers grown thereon. The epitaxial layer may cover an upper portion of the fin body. The epitaxial layer may be formed on a surface of the fin body by a selective epitaxial growth (SEG) process. Electrical characteristics of the semiconductor devices may be affected by electrical characteristics of the fin bodies. For example, the electrical characteristics of the semiconductor devices may be affected by the electron mobility of the fin bodies.